The invention is based on the fact that, during supply of liquid to a drilled injection well at high injection rates, fractures may occur that propagate from the drilled injection well through those areas of the formation that have inherent weaknesses and/or in the direction of the maximal horizontal stress σ′H of the formation. These fractures are undesirable in case they mean that liquid flows away uncontrollably from the drilled injection well directly into either the first or the second adjoining drilled production well, which would mean that the operating conditions are not optimal. However, in general the formation of fractures has the advantage that the supplied liquid can more quickly be conveyed into the surrounding formation across a larger vertical face and is thus able to more rapidly displace the contents of oil or gas.